Encryption is mostly used to remove clear passwords from settings (database or SCM credentials for instance). The implemented solution is based on a symetric key algorithm. The key point is that the secret key is stored in a secured file on disk. This file must owned by and readable only by the system account that runs the SonarQube server, the analysis with SonarQube Runner, SonarQube Ant Task, Maven or from the Continuous Integration server.

The algorithm is AES 128 bits. Note that 256 bits cipher is not used because it's not supported by default on all Java Virtual Machines (see this article).

1. Generate the secret key

A unique secret key must be shared between all parts of the SonarQube infrastructure (server and analyzers). To generate it, go to Settings > General Settings > Security > Encryption and click on Generate secret key:

2. Store the secret key on the SonarQube server

Copy the generated secret key to a file:

sonar-secret.txt

Store this file on the machine hosting the SonarQube server (default location: ~/.sonar/sonar-secret.txt). If you want to store it somewhere else, set its path through the sonar.secretKeyPath property in SONARQUBE_HOME/conf/sonar.properties:

SONARQUBE_HOME/conf/sonar.properties

Restrict its access to the system account running the SonarQube server (ownership and read-access only).

Restart your SonarQube server.

3. Generate the encrypted values of your settings

Go back to Settings > General Settings > Security > Encryption and generate the encrypted values of your settings: